The present invention relates to digital servo systems and, more particularly, to multiple channel servo (MCS) systems utilizing an application specific integrated circuit (ASIC).
It is known to use microprocessor controllers for the real-time control of certain machine operations. To illustrate, a mail processing system may be comprised of a envelope feeder mechanism for receiving a stack of envelopes and, in a serial manner, serving up the envelope to a sealer-transport mechanism. The sealer-transport mechanism is charged with the function of sealing each envelope as it is caused to traverse a sealing apparatus and to serve-up the envelope to a mailing machine. It is known to also employ a scale mechanism located between the sealer-transport mechanism and the mailing machine. The scale mechanism is charged with the function of weighing the envelope by means of a scale, and determining the required postage value and communicating the postage value to a postage meter. In similar manner, a transport mechanism, customarily integral to the scale mechanism, must assume physical control over the envelope for positioning the envelope on the scale and thereafter serve-up the envelope to the mailing machine.
Generally, the mailing machine will include a transport mechanism which assumes control over the envelope and deliver the envelope to a printing station whereupon a postage meter will print a postage indicia on the envelope. The mailing machine transport mechanism will again assume control of the envelope and eject the envelope from the mailing machine.
In the afore-described mail processing system, envelopes are processed in a serial manner. In such mail processing systems, it is known to provide each of the cited mechanisms with a motor or plurality of motors to act as prime movers for the associated mechanisms. As is known, each motor or group of motors is under the control of a respective microprocessor motor controller acting through a respective driver board. It is also known to provide the respective driver board with a servo ASIC associated with each motor or group of motor requiring servo control.
Such mail processing systems as afore-described have required the use of multiple microprocessor motor controllers and associated servo ASIC's.